Various Governmental Agencies require that new homes have included therein a smoke and fire alarm system, and it is sometimes further required that the alarm system utilize an extraneous or supplemental source of current, so that should the electrical wiring become damaged during a fire, the smoke and fire alarm will remain operative. The extraneous source of current is usually a storage battery. Many conscientious people purchase smoke and fire alarm systems and install the system in their home. After the novelty of enjoying the safeguards brought about by the presence of the alarm system has become familiar, most people generally are inclined to thereafter neglect the system; and accordingly, as time progresses the storage batteries contained within the alarm device become useless, thereby rendering the entire failsafe aspects of the system inoperative.
It is therefore desirable to be able to provide a smoke and fire alarm system which normally utilizes a domestic current source for sounding an alarm, and upon current failure the system utilizes mechanically stored energy to signal the loss of current. It is furthermore desirable that the alarm bell of the present invention include means by which it can also be used as a burglary alarm.